Apoptosis is an active process of cell death that occurs through the regulation of various gene expressions and protein activities in cells according to programmed signals. Apoptosomes formed through this process are removed by the action of phagocytes such as the surrounding cells or as macrophages, such that they do not cause inflammation. Such apoptosis is frequently observed in various normal physiological processes of living organisms and known to be deeply involved in the process of development of various diseases. Namely, the development of abnormal apoptosis can lead to neurodegenerative disorders, immune disorders and cardiovascular diseases, and the abnormal inhibition of apoptosis can cause cancer.
More specific examples of diseases which are caused by the abnormal development and inhibition of apoptosis include cancers induced by the abnormal expression of genes such as p53, p16 and Bcl-2, infections with HIV Herpes and influenza virus, and autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, multiple sclerosis and myasthenia gravis. The apoptosis of cells of an individual is a general mechanism for removing abnormal cells, that is, unrecoverable genetically damaged cells, from the individual in order to prevent the development of tumors caused by either the genetically damaged cells or the induction of inappropriate differentiation by differentiation stimuli. This concept is supported by the fact that general anticancer agents induce the death of cancer cells through an apoptosis process associated with the inhibition of proliferation of cancer cells (Barry, M. A. et al., Biochem Pharmacol., 40:2353, 1990; Hickman, J. A., Cancer Metastasis Rev., 11:121, 1992).
Accordingly, the disturbance of apoptosis process induces the survival of damaged cells and cells that started to be damaged and the growth of these cells, and thus the inhibition of apoptosis plays an important role in a carcinogenic process. In addition, it has been reported that substances having cancer preventive effects induce the apoptosis of such abnormal cells and that the induction of apoptosis by these substances is associated at least with the cancer preventive activity thereof (Fesus, L., J. Cell Biochem., 22:151, 1995; Reddy, B. S., Cancer Res., 57:420, 1997)
Meanwhile, enormous research expenses have been paid for studies on the mechanism of development and treatment of cancers, but cancers still remain as incurable diseases, and various cancer therapies cause side effects (Goodman et al., Cancer Res., 9:2295, 1987). Accordingly, many efforts have been made to study and develop novel drugs and formulations for inhibiting cancers, and particularly, studies on the development of anticancer substances from natural materials having small side effects have been drawing interest.
Some of the present inventors developed a method for providing cambium- or procambium-derived cell lines which overcome the problem of variation caused by dedifferentiation, can stably proliferate and has high genetic stability, and found that, when a Taxus-derived cell line among the cell lines is cultured, paclitaxel is obtained at a high yield (PCT/KR2006/001544). However, the anticancer effects of a Taxus cambium- or procambium-derived cell line itself have not yet been reported.
Accordingly, the present inventors have made extensive efforts to develop a natural material-derived anticancer composition, which has minimized side effects compared to the conventional anticancer agents and shows excellent anticancer activity, and, as a result, have found that a Taxus cambium- or procambium-derived homogeneous cell line; a lysate thereof, an, extract thereof; or culture thereof shows cancer cell-killing activity, thereby completing the present invention.